Growing Process of Watermelon

Planting

• Watermelons need warm soil to grow, so it's recommended that you start your seedlings indoors or in a greenhouse, if you have one. To make sure your seedlings are ready for the outdoor season, plant them six weeks before the last frost in your area -- mid- to late April in most parts of the country. For best results, use sterilized soil and maintain a soil temperature of about 75 degrees Fahrenheit. Plant seeds 1/2 inch deep.

Transplanting

• A week before you plan to transplant your melons, cover the outdoor plot with a sheet of black plastic to increase the soil's temperature. You should move your seedlings outside only after all risk of frost has passed. Plant the melons in rows, 4 to 6 feet apart, leaving 48 inches between seedlings. Watermelons need heat to fully develop, so plant the seedlings in the warmest, sunniest spot in your garden. To give your young plants a strong start, add some compost, 1/4 cup of lime and 1/4 cup of bone meal to each planting hole.

Flowering and Growing

• Water your plants every day. Keeping the soil moist is important, since the vines could drop the developing fruit early if the garden gets too dry. Feed regularly with a balanced fertilizer. Plants grow female and male flowers. The male blossoms that come first don't produce fruit. Female flowers, which have distinct bulbs at their bases, appear later in the season. Watermelons need about three months of warm weather for fruit to develop fully. If you live in an area with a shorter growing season, row covers help keep the soil warmer through June. You should also look for watermelon species classified as early maturing varieties. Smaller, 5- to 10-lb. melons, including Baby Delight, Northern Sweet and Sweet Siberian, tend to fare better in northern climates than their 25- to 40-pound cousins.

Harvesting

• Watermelons mature in late August to early September, depending on your climate and the type of melon you choose to plant. Letting fruit fully mature on the vine is important, since watermelons don't ripen further after being picked. A watermelon is ready when the curly tendril branching off the stem that holds the fruit has turned brown and dry. Check the underside of the melon. If it has a yellow tinge, the fruit is ready to harvest. Knocking on a ripe melon produces a hollow sound. To avoid vine rot, cut the melon from its stem instead of attempting to pull it free.